The purpose of this study is to determine whether individuals who have been refused a kidney transplant because of high levels of anti-HLA Class I cytotoxic antibodies produce a limited type of idiotype that may be a target for interventional therapy. The specific purpose of the use of the UW-GCRC is to enable the collection of large quantities of leukocytes using a leukapheresis procedure that can be subjected to studies of B cells which are rare components of peripheral blood and thus can make our studies possible.